Oil-burner control



Feb. 28, 1928. 1,660,959

J. G. Geom-IUE ET AL OIL BURNER CONTROL Filed May 11. 1925 4Sheets-sheet 2 f'afwws W J M v www. @4f- Feb. 2s, 192s. A 1,660,959

' J. G. GOODHUE ET AL OIL BURNER CONTROL Filed May 11. 1925 4sheets-sheet 5 Feb. 28,1928. 1,660,959

J. G. G-OODHUE ET AL OIL BURNER'CONTROL` Filed May 11`, 1925 4sheets-sheet 4 a UNITED STAT 'nieuwe Fea'pzs, 192s.

Es PATENT oFFICE.

JULIAN e. eooDHUE, or EvmsroN, ANnrmmEn'rJ. SAUVAGE, or cmoaeo, 11.1.1-A

NOIS, ASSIGNOBS TO 'ELECTRO 'THEBHOSTATIC ILLINOIS, A GOMMON-LAW TRUST.

OIL-BURNER CONTROL.

vApplication led Iay 11,

The purpose'of this invention isto provide a reliable and safe means forcontrolling the operation of oil burning or otherfluid fuel furnaces. Itis mainly the purpose of theinvention to insure that injection of fuelinto the furnace will be stopped,`unless all parts of the apparatus, arein proper conditionfor functioning in the intended manner. In carryingout this purpose, there is Vprovided a plurality of mercury switches forcontrolling the circuit of the ignition means and operating motor, allof said switches being normally open when the apparatus is at rest.These switches also control means for insuring the correct successiveoperation thereof, and means are provided rendering'KA being arrangedthe switch operating mechanismv ineffective in case of a drop in voltagein the line, sufficient to endanger the proper functioningof` theignition means of the oil burner or the motor for operating the oil pumpand air delivery means. Other features of the invention are directed topreventing operation of the motor in case the ignition means isv burnedout or otherwise fails to function;

and to provide a temperature controlled device, for instance, in thestack oroutlet flue of the furnace, having the function of coritro'llingthe electric motor circuit so'tha't in' case an operation is started'and the proper heat fails to develop within a, predetermined time, themotor circuit will be opened and the entire apparatus permanently lockedagainst operation until manually readjusted, as required for successfuloperation.

The objects of the invention are accomplished by a control system, asillustrated in the drawings, whereinfling and timingunit, partly in Fig.1 is a front view of a furnace showing the. oil burning apparatus, and`in di the various electrical and thermostatic oon-Y trol devicestherefor. Y Fig. 2-is a plan view of the oil burning apparatus, partlyin section, to showthe location of electrical ignition means therefor.

Fig. 3 is a side view of a temperature responsive elementpreferablylocated Ainthe outlet flue of the'furnace, and showing this iiue insection.l Fig 4. is a face view of a circuit controlsection, and

with the coverremoved.

`the boiler of the furnace.

1925. Serial No. 29,640.

Fig. 5 is a side view of the. mechanism shown in Fig. 4.

Fig." 6 is a vertical sectional. view taken on the line 6 6 of Fig. 4.

Fig. 7 is a horizontal sectional view taken on the line 7--7 of Fig. 4:.

Fig. is a separate detail view of the igniion s4w1tch part of themechanismshown in Fig. 9'is a detail taken on vtheline 9-9 of Fig. 8.

Fig. 10 is a simplified diagram ofthe circuits shown in Fig. 1.

lhe control apparatus illustrated comprises thermostatically controlledcircuit operating devices, a plurality of thermostats in series, wherethe heat i's to be delivered, another in able thermostat has its heatresponsive elemen-t'inthe stack or outlet flue of the furnace. Thethermostat in the place to be heated, or what maybe termed a roomthermostat, is in series with theboilerthermostat, so that 1t isnecessary for both of these thermostats,'upon a Areduction in thetemperature controlling the saine, to move their respective switches toclosed position in order to start the operation of the oil burner andcontrolling devices therefor. Upon a rise in temperature sufficient tocause either the room thermostat or the boiler thermostat to open itsrespective switch, the operation of the oill burner is discontinued.

The invention to which this application for patent 1s `directed is notso much in the specific construction of the individual devices employedin the system as in the ooactiontbrought about between these variousdevices, in orderto safelyand reliabl control the operation of the oilburner. the

following description, the general arrangement of the control apparatuswill first be po ted out and then more particular attention will be'givento the details of the oonstruction. i

` Referring to Fig.` 1-, a front view of a furnace and boiler 1 isindicated, the oil burner being shown at 2 and comprising means forjectng into the. furnace 'atomized liquid fuel Ythroughthe nozzle 3.'The oil pump is at 4 and blower at 5, and a mo- GONTROL COMPANY, OFCHICAGO,

one in the place A third dependf ated by solenoid 19. The

v the circuit of the ignition a switch 21. This switch is indicated moretor at 6 for operating the pump and air blower. Electrical ignitionmeans 7 receives current from the wires 8 and 9, leading to transformer35. The circuit of the transformer is controlled by a switch 21 oper--solenoid is in a branch circuit from a source of current indicated bythe line wires 10 and 11, and which follows the conductor 12 leading toswitch 13 of room thermostat 14, wire 15 -leading to the switch 16 ofthe boiler thermostat 17, wire 18 to solenoid coil 19 and from thesolenoid coil through conductor 20, returning to the line wire 11. Thefunction of solenoid 19 is that of a relay for controlling device 7through in detail in Fig. 8. When both switches 13 vand 16 are moved toclosed position, due to the cooling and contraction of their respectivetherniostats 14 and 17, coil 19, becoming energized, lifts its movablecore 22 which carries a rod provided with a collar 23 for engaging thepivoted switch support 24.

Rocking this switch support upwardly around its, pivot- 56, resultsin aglobule of mercury 26 rolling from the right hand 'end of the containingtube to position for closin the contacts 27. These contacts, when closeserve to permit current to iow through the transformer 35 for the'ignition device 7, the

circuit of which may be traced in Fig. 1`

from the line wire 10 through conductors 12, 28 and 29, through theswitch 21, conductors 30 and 31, conductor 91 through the transformer 35(Fig. 2), and conductors 36 and v 37 to the line wire 11.

At the same time that the ignition transformer 35 is made operative, theheater coil 32 (Fig. 4) is energized. This coil is connected at posts-92(Fig. 1) between conductors 31 and 20, the circuit ofthe coil, like thatof the ignition device 7, being closed by switch 21. within thecontainer38, which, atthe bottom through an aperture 39, communicates with theinterior of an expansible bellows motor `34. The volatilization of theliquid in container 38 results in extending the bellows 34 downwardly,the support 40 therefor being loca-ted at the upper end of the motor.The disk 41 at the lower end of the motor is provided with a seatfor-engaging the conical 'y end 42 of a plunger 43, guided in bearing 44and carrying a dash pot piston 45 at its lower end. The function of thedash pot 46 is merely to slow up and steady the motion either under theaction of the expansion motor 34 or a restoring spring 47,bearing'between the upper end of the dash pot and a collar 48, anintegral part of the plunger. This plunger is also provided with ayrecess 49 through which passes a switch operating' lever 50 pivoted tosupport2 the left hand end rangement the switch 53 may be opened.

The coil 32 warms the liquid.

ing frame 51 by.a pin 52. The heat motor 34 has a slow steady action asprovided for by the effectiveness of the heating element 32 and thenature of the liquid within the motor, and the resistance of spring 47and the dash pot.

Thus a-denite time is required after the closing of the ignition switchto cause the switch operating lever 50 to move downwardly far enough tooperate the motor control switches 53 and 54, shown in Figs. 4 to 7, andd'iagi'ammatically in Fig. 1. It may bc seen in Fig. 4 that the switches53 and 54 are, supported at different inclinations on lever 55 pivotedupon-pin 56, and therefore when theswitch operating lever 50, whichcarries a depending finger 57 for engaging of switch support arm 55(Fig. 4), is in its extreme lower position, both of the switches 53 and54 will be closed, but upon a rise of lever 50 toward its normalposition, the switches53 and 54 will open in succession. The purpose ofthis aris to maintain the vmotor circuit closed under proper conditions,even though When the switch operating arm 50 is lowered by theheat motor34, the circuit of the motor 6 .is closed, due to the position ofswitch53, the mercury therein then closing the circuit through thecontacts 58 (Fig. 1). x The motor circuitjthrough the switch 53 may betraced, as follows, from line eonductor 10 to conductors 12, 28 and 29,'switch 53,

conductors 59 and 60, motor 6, conductors 36 and 37 to line wire 11.Thus only after .-a predetermined interval, after closing the circuitofthe ignition means,`is the motor started, resulting in the injection'of atomized fuel into the furnace, its. ignition `and the delivery ofair-required for combustion. A stack-thermostat 61 provided in order tocontrolthe motor circuit particularly to open it incase the ignif tiondevice fails, or for other causes combustion doesnot occur, after themotor circuit is closed. This stack thermostat is in. the form of acoiled tube, 'one end of. which is closed andthe other end of whichcommunicates through a conduit 62 with an expansion motor 63. The coil61, tube 62 and expansion vmotor 63 are preferably illed with nitrogengas, the change of prsure of which results in expansion and contractionof themotor 63. 4This motor is'v supported at its Ybase on 'a bracket64, Figs. 4l

and 5. Upon expanding, it pushes upwardly upon a yoke 65 the lower endof which yoke is attached to one end of a spring 66. The other end ofthe spring 66 is wrapped aroundpost 67. Thus, the expansion of the motoris against the action of spring 66. The movable yoke 65 carries aforwardly eX- tending arm .68.` This arm is` vertically drilled toreceive a bushing 69, the function` (Figs. 1 and 3) is of which is tofrictionally engage a switch operatin rod 70, and is an importantfeature of t e apparatus. When the motor expands, rod 70 is carriedupward" rocking a switch supporting member -71 tothe right, Fig. 4,around its pivotal support y72, on an extension 73 ofthe fixed bracket64.

The contacts 75 of the meieury switch 74 are at the right end of the`Sallie. Therefore, when the switch is rocked to the right the mercury 76thereinwhich is normally at the left end of the switch, rolls down tothe right end, closing a circuit controlled by the switch. This circuit,as may be seen from Fig. 1,v passes from the line wire 11, conductors 37.and 36, through the motor, then along `conductor 60,' conductor 59,switch 54, along conductor 77, through the expansion motor switch 74,conductors 78, and 418, boiler switch 16, and back'through conductor 15and switch 13 of room therv mostat 14, conductor 12 to line wire 10. The

the motor to continue to operate after its circuit is first closed, onlyin case some predetermined minimum rise in temperature is 'effected atthe outlet stack of the furnace. Accordingly, if for any reason whatevercombustion should fail totake place, the outlet stack of the furnacewould remain cold and consequently the expansion motor 63 would fail tofunction, leaving the motor circuit open. `The switch 53, which is inparallel with switch 54, as previously described, originally serves toclose the motor circuit, but this switch is again opened by a timingmechanism, and therefore, if in the meantime the expansion motor switch74 is not closed, the motor cannot continue to function.

The timino mechanism includes a heat motor 34f(F1g. 4), the lower end ofwhich,

, as previously described, bears ,upon the i sition.

plunger 43-for operating the switch lever- 50. This lever in. itsdownward movementaroundthe pivot-'52 first serves to rock both of themotor switches53 and 54 to closed posit-ions by arm 57 thereof engagingthe pivoted switch supporting .lever 55, and arm 57, upon furtherdownward movement of the lever 59, engages ignition switch support 24rocking this switch to the off po- The downward motion of switch support24 vby engaging disc 23- forces the armature 22 down,..although solenoid19 is v still energized.

At the same time lever 50 serves to rock a bell crank lever 79downwardly around the pivotal support 8() therefor. The small armv 81 ofbell crank lever 79 extends between a pair of pins 82 and 83 carried byarm 50, and spaced apart soas to provide lost-'motion between. the arm50 and the bell crank lever. Thus, after' the lever 50 is forceddownwardly part Way by the heat motor 34,

pin 82 engagesthe bell crank lever, rocking 1t into posit ion, ras shownin Fig. 8, to prevent4 the ignition switch 21 from y'being drawn back toits closed. position by solenoid 19. f

When the arm 57 of lever 50 engagesthe supporting arm of the switches 53and 54,

rocking both of the switches` to closed pospring 47, Fig. 4. Theignition switch, asy

previously described, is first rocked toits closed position by theaction of the armature-22 of solenoid 19. Then the next thing thathappens upon the downward motion Nof arm50 is t9 start the motorand thenopen the` ignition switch, lwhich includes in its circuit the heatingelement 32 of heat motor 34. Accordingly, after the opening of theignition switch'the heat motor' 34 gradually contracts, and arm 50slowly returns upwardly, but is` stopped after the upward motion issufficient to open switch 53, but' not sufficient tofopen switch 54.Means for stopping 4the switch operating arm 50 at the desired positionis the latching element 84 carried by the weighted lever 85, andcoacting'with another latch element 86 on the vswitch operating arm 50.The weight 87 of lever 85 is to the left of its pivot 88. The switchoperating burner continues to function until the circuit of solenoid 19is opened either at the room thermostat 14 or tlie boiler thermostat 17.The switchesfor these thermostats open when the predeterminedtemperature is reached for which the thermostats are set '105 lever 50..is held in thls posltlion, and theI oil foroperation. Upon the openingof the ciri cuit of solenoid 19 its armature 22y is released, and by itsweight depresses the right hand end of the latch-supporting lever 85,'releasing lever 50 and permitting all switches to return to openposition, and-the rise of lever 50'also results in pin 83 thereofrocking the bell crank lever 79 back :to its normal position.

The lever 79, because of spring 90 (Fig. 9),always remains in theposition to which it has been set-by t-lie'pin's 82 or 83 of lever 5()until the lost motion between thesepins and the bell crank-lever "istaken u The purpose of the lostV mot-ion between tie pins is mainly.to'permit the Switch operating lever 5() to` return Vtoward its upperposition without releasing. the igthe tension of nition switch until thelast'part of the upward motion, of lever 50. Therefore, if the roomthermostat switch 13 and the boiler thermostat 16 should move to closedposition before .the lever 50 is completely refturnedtto its .normalsupporting position,

the ignition-switch could not be closed until the belll crank lever 79is rocked into position to release the ignition switch. i

The operation of the'thermostatic control means is necessarily somewhatinvolved, due

:to the necessity of meeting several contingencies that may arise-in theoperation ofthe oil burnergsuch as unintended manual interference withthe operation of the thermostatic switches, or possibly the automaticoperation thereof before all parts off the apparatus are restored tonormal position from vwhich ,the intended cycle Aof operation Assumingthe lever and parts con- 'trolled thereby are in their normal startingposition and the solenoid 19 is de-energized, with its armature dropped,as indicated in Fig. 4, then 'if both the boiler.

thermostat switch 16 andthe room thermostat switch 13 are closed,because ofthe con` traction of their respective thermostats un= der the'iniuence of'. some predetermined expansion of motor'34 (Fig. 4) thenslowly rocks lever' 50 downwardly. The arm 57 of this lever firstengaging the' left haindv end of theJ motor switch supporting arm 55,first the closing of switch 53, the motor 6 ig. 1) is set in operation,which causes the delivery-of 'ai'r and atomized fuel to the oil burner.Thev fuel is immediatelyignnea by the igniter. 7 which has had ampletime, be-

tween the closingof its switch 21 and the closing of switch 53,'to burnoii any carbon or. other obstructing matter which might in terfere withthe' proper .jumping of the spark.- Switch 54 fis 'in circuit with thevswitch 74 under the control of the 'stack thermostat expansion motor63. Therefore, ifcombustion `takes-place, as intended, the stackthermostat will be raised inv tempera'- ture suciently to close switch74 and the current for operating the motor may, :there-i fore,passthrough both or-.either ofswitc'hes V53 and 54, when vtheswitchoperating mechaj fnlsm is Avin its lowermost position.l

pon further downwardA movement of the switch `operating lever 50, after'the motor switches 5 4 and 53 are closedfor a definite period, the arm57 thereof engages the switch supporting arm 24A (Fig. 8) of theignition switch rocking this switch to the open position indicated inFig. 8, and

against the pull of solenoid coil 19, as the switch operating arm 24bears against the disk 23 movable with the core 22 of the' solenoid.

' As the lever 50 nears its llower-most position, pin 82 thereon engagesbell crank lever- 79 rocking the latter into `lockingposition above theswitch supporting arm 24. Due tov the resist-ance fof spring 90 bearingagainst the bell crank lever 79, this lever remains in locking positionduring the return of the switch operating lever 50 until pin 83 thereofengages the bell crank lever and restores it to a position where it willagain permit the solenoid to throw the ignition switch to the onposition, provided the .ver` 55. When either3 the room thermostat rroomthermostat switch 13' and the boiler thermostat switch 16 allow thecurrent to switch13 or the boiler'thermostat switch 16 open, because ofa rise ina temperature to some predetermined point, the armature 22falls, engaging the right hand end of weighted latch lev'er l85, rockingthe latch 84 away from the coacting element 86 on the lever 50. Then thelever 50 'rises to its initial position,

roekingbell crank lever 79 away fromr the switch support 24, and allparts of the a paratus are then in normal position rea y .to repeat thecycle of operations. closing the switch 54 and then the switch 53.

The( stack `thermostat 61 'performs the function ,of maintaining themotor circuit closed, in case required heat is developed within the'timelimit provided for combusj. .tion to take place'. Stack thermostat,therefore, also functions to hold the motor circuit open in v'case of'failure of combustion. In

this regard it coacts with` theV switch 54 first movedto the open4position, due toits different inclination .on .the switch supporting arm55 than the switch 54: Therefore, the operating motor cannotreceivecurrent throu h the switch -53' after a predetermined time om thestarting of the motor, but will vreceive current through the switch 54whilel the lever 50is retained v,against further up.- ward movement bythe latch 84, provided the stack thermostat switch 74 is in closed ne iposition, this switch being inseries with the motor and switch 54. Thepositionof stack thermostat switch 74 is dependent upon the temperatureoi the stack thermostatie device, the switch remaining open and themotor is stopped unlessthe desired rise in temperature occurs at thestack thermostat. Therefore, the continued operation of the oil burneris dependent upon its development l of some ixed minimum temperature.

To review the operation in connection with the circuit diagi'am shown inFig. 10, in which the normal condition is shown, when the twotheri'nostat's, the boiler tlierinostat 16 and the room thermostat 13,close, the solenoid is connected from the line 11 through the twothermostats to the line 10. As explained above, energizing the solenoid19 causes the starting switch 21 to close. A circuit is then .connectedfrom line 10 through the switch 21 to two branches, one of which passesthrough the primary wind ing of the igniter coil 35 to 'the line 11, andthe other branch passes through the coil of the heat motor 32 to theline 11; Although but 011e specific embodiment of this invention hasbeen herein shown and described, it will be understood that numerousdetails of the construction may be altered or omitted without departingfrom the spirit of this invention as defined by the following claims.

We claim: v

1. In an oil burner control apparatus, the combination with an oilburner and means for supplying fuel and air to said burner and ignitionmeans, of a circuit for controlling said ignition means, said circuitincluding a switch, electro-inagnetic means for operating said switch,therlnostatic means for controlling the operation of saidelectro-magnetic means, and a timing mechanism arranged to automaticallyresist the o eration of said electro-magnetic means a ter apredetermined length ottime.

v2.1m an oil burner control apparatus, the combination with an oilburner and means for supplying fuel and air to said burner and ignitionmeans, of a circuit for controlling said ignition means, said circuit`including a. switch, electro-magnetic means for `operating Said switch,thermostatic means for4 controlling the operation of saidelectro-'magnetic means, and a timing mechsaid motor andelcctricalignition means,

said circuits including a plurality of nor`-` mally open switches, meansvfor operating said switches iucluding'an electrically lieated expansionmotor and electro-magnetic means, said electro-magnetic means being,

under thevcontrol of a Vtherinostaftically operated switch and arrangedto close one of said plurality of switches with which the ignition meansis in Aseries, an electrical heating elenient for said expansion motoralso in series with said switch, means operated by said expansion motorfor closing two oi' said plurality ot' switches, said two switches beingarranged to be normallyv urged toward their open position and being inshunt with each other 1n the motoi` circuit, andan additional switch inseries with one of said switches, and temperature re' sponsive means foroperating said addi- Ational switch, said temperature responsive meansbeing arranged to be influenced directly by the heat of combustion,means operated by the switch operating nieans under t-he control ot' theexpansion motor for locking one of said motor switches in closedposition after its companion switch is permitted to ret-urn to openposition, andA said electro-magnetic means being adapted to release saidlocking means.

Signed at Chicago this 7th day of May,

JULIAN G. GrOODHUE.v HERBERT J. SAUVAGE. v

